1. Technical Field
This invention generally relates to the field of fire protection, and more specifically relates to apparatus and methods for inhibiting the spread of fire and smoke.
2. Background Art
Various fire protection devices are known in the art. For example, fire doors have been used to inhibit the spread of fire between different parts of a building. When a fire alarm sounds, fire doors are typically shut and are not to be opened until the threat of fire has been eliminated.
Some devices in the prior art provide a curtain that inhibits the spread of fire. For example, one example of a prior art fire curtain is shown in U.S. Pat. No. 5,809,699 “Fire Curtain”, issued on Sep. 22, 1998 to Joly. The '699 patent discloses a two-walled curtain that deploys from a ceiling. Water is sprayed from the top of the curtain between the two walls onto the inside surface of the two walls. The water runs down inside surface of the walls and accumulates in the bottom to form a seal with the floor. A drain opening near the bottom of the curtain drains away the water so it does not spill on the floor, and keeps only a small amount of water in the bottom of the curtain.
One significant problem with the fire curtain disclosed in the '699 patent occurs when water flow stops. Oftentimes during a fire, a sprinkler system will function for a short period of time, but the fire itself or a collapsing structure can cause the sprinkler system to fail. With the fire curtain in the '699 patent, once the water system providing the water spray fails, there is no water to cool the inside walls of the fire curtain. Thus, once the water system fails, the fire curtain would quickly fail as well.
Another problem with the fire curtain in the '699 patent is that it is a single, hollow baffle that spans from ceiling to floor between two walls, and thus provides a barrier to persons who may need to pass. Of course, a fire is an event where people may need to evacuate. The '699 fire curtain may serve to retard the spread of a fire, but will also inhibit the evacuation of people. What is needed is an improved fire protection device that provides enhanced fire protection even when the water supply fails, and through which people may easily pass during a fire.